(c) Review and revise relevant legislation, policies and practices related to immigration detention to ensure that migrants are not detained arbitrarily, that decisions to detain are based on law, are proportionate, have a legitimate purpose, and are taken on an individual basis, in full compliance with due process and procedural safeguards, and that immigration detention is not promoted as a deterrent or used as a form of cruel, inhumane or degrading treatment of migrants, in accordance with international human rights law;